1. Field of the Invention
This application relates to a surgical instrument and more particularly to a surgical instrument for both grasping and cutting tissue.
2. Background
In minimally invasive surgery, the surgical procedure is performed by access to the surgical site through one or more small incisions. The surgical site is visualized by an endoscope inserted through one of the incisions and various surgical instruments are inserted through the incisions to manipulate the tissue as desired. The advantages of minimally invasive surgery are well established which include improved cosmesis, reduced chance of infection, faster patient recovery time and lower hospital costs.
Minimally invasive surgical procedures typically require the tissue to be grasped and held or manipulated. These procedures also typically require the tissue to be severed. Currently, to perform cutting and grasping functions separate instrumentation is required. This results in the time consuming task of withdrawing one of the instruments from the incision (usually through an access port such as a trocar extending into the patient) and inserting another instrument through the port. Not only does this take up valuable surgical time, but there is an increased chance of infection by passage of the instruments outside the body. There is also the risk of damaging tissue as the second instrument is inserted and advanced to the surgical site.
In these minimally invasive procedures, oftentimes the grasper jaws are used to dissect tissue. This can be achieved by opening the jaws to dissect the tissue with their outer portion to create a working space for access to the surgical site. During this dissection and instrument advancement, a vessel may be encountered which requires severing to provide further access to the surgical site. The surgeon sometimes cauterizes the vessel to sever it, but such “excessive cauterization” could damage surrounding tissue. Another alternative utilized by the surgeon is to remove the grasper and insert a pair of scissors or shears to sever the vessel. This instrument exchange has the disadvantages enumerated above. Additionally, after severing, to continue dissection, the scissors would have to be removed and a grasper reinserted. If another vessel requires cutting, an exchange for a scissor would again be necessary. As can be appreciated, multiple instrument exchanges could occur, thereby multiplying the foregoing risks. Some surgeons might try to use the open scissor jaws for dissection, but there is a risk of inadvertent cutting of tissue, so exchanging for a grasper is preferred.
Another example where currently instrument exchange between a scissor and grasper is necessary is in laparoscopic cholecystectomy. In this procedure, typically open jaws of the grasper are used to dissect around the bile duct and then a clip applier extending through a different access opening applies one or more clips on each side of the target area of the duct. The surgeon then needs to remove the grasper and insert a scissor to cut between the clips. Next, the scissors need to be removed so that graspers can be inserted to remove the gall bladder. As can be appreciated, exchanges of the grasping and cutting instrument are required.
It would be advantageous to provide a single instrument which achieves both cutting and grasping which would thereby avoid the disadvantages enumerated above of instrument exchanges. This was recognized in U.S. Pat. Nos. 6,391,043 and 7,410,494, commonly owned with the present application. However, there are several disadvantages associated with the instruments of these two patents. The present invention advantageously overcomes the disadvantages of these instruments and provides an instrument for both cutting and grasping tissue which provides significant manufacturing and clinical advantages.